Here’s a quick trick you can use that pipes the output of the mysql command directly to redis-cli, bypassing middleware and allowing both data stores to operate at their peak speed.
Using this technique I was able to reduce my load time of ~8 million rows from 90 minutes down to two.

Used at YouTube. It acts as a front-end to MySQL providing an RPC interface that accepts and transmits SQL commands. It is capable of efficiently multiplexing a large number of incoming connections (10K+) over a small number of db connections at reasonable throughput (~10kqps).

MySQL joins are very powerful, but can at times cause confusion. Do you go for a left join, a right join, or an inner join? What is the actual difference between them and how do you use them to pull information from two or more tables?